Mavenize the OpenHIM project

I'm tentatively opening this PR so that we can discuss if everything works ok. @devcritter do you think you can checkout this branch and see if it build correctly on your machine as well.

You may want to see here for detail of working with maven in Mule Studio: http://www.mulesoft.org/documentation/display/current/Converting+Studio+into+Maven

Linked to #93